a recovering addict, the substance she abused, food. the former plus-sized model wasn't overeating, she was out of control. >> give me the experience. >> i would get wing, ben and jerry's and that meal alone was probably around 6,000 calories if not more. >> reporter: by the age of 22 she tipped the scales at 316 pounds and then decided to shed the weight in the most public way possible on the tv show "the biggest loser" she lost an astonishing 155 founds. landed on the cover of magazines like ok! and woman's world. when she started to creep back, she realized it was not about her body but mind. doctor says tara is not alone.